Impact of vegetation geometry and distribution on bedload transport

沿海沼泽减弱风暴潮和波浪，保护生命和财产。这种绿色基础设施还改善了水质，并为具有重要经济意义的渔业提供了栖息地。类似地，洪泛区植被减少洪峰，增强河岸稳定性，并减少河道的营养物负荷。由于这些好处，资源管理人员提倡对沿着走廊和沿海地区的植被景观进行重新种植和生态管理。美国每年花费数十亿美元来恢复这些景观。恢复工作包括恢复植被和将沉积物转移到受侵蚀地区，需要对植被覆盖地区的沉积物迁移和保持有基本的了解，而本项目将有助于提供这种了解。除了这些理想的社会效益，可以从这项研究中产生，该项目还将培养一名博士生，支持一名本科生，每年夏天，并包括在波士顿地区的初中和高中的推广。新的模型将通过一系列实验室实验开发，使用日益复杂的模型植被，这将建立一个了解如何植被的几何形状和分布在一个通道内的影响速度，湍流和泥沙输运。实验将记录流速和河道尺度的沉积物通量，并将使用激光扫描跟踪水深演变。通过与美国垦务局的合作，将促进新模型在全面恢复项目中的实际应用。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Coastal marshes attenuate storm surge and waves, protecting life and property. This green infrastructure also improves water quality and provides habitat for economically important fisheries. Similarly, floodplain vegetation reduces flood peaks, enhances bank stability, and reduces nutrient loading to river channels. Because of these benefits, resource managers advocate the replanting and ecological management of vegetated landscapes along river corridors and in coastal zones. The US spends billions of dollars each year to restore these landscapes. The restoration efforts, which include the re-establishment of vegetation and the diversion of sediment into eroded areas, require a fundamental understanding of sediment transport and retention in vegetated regions that this project will help provide. In addition to these desired societal benefits that could stem from this research, the project will also train one doctoral student, support one undergraduate student each summer, and include outreach in Boston-area middle and high schools.This research project will develop physical predictions of sediment transport as a function of flow and vegetation characteristics. The new models will be developed through a series of laboratory experiments using model vegetation of increasing complexity that will build an understanding of how vegetation geometry and distribution within a channel impact velocity, turbulence, and sediment transport. Experiments will record velocity and channel-scale sediment flux, and will use laser-scans to track bathymetric evolution. The transfer of new models to practical application in the full-scale restoration projects will be facilitated through collaboration with the US Bureau of Reclamation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.